Question: $\sum\limits_{j=1}^{2 }{{(j^2 + 1)}}=$
What is the question asking for? $\sum$ tells us to find the sum. The question is asking for the sum of the values of $j^2 + 1$ from $j = 1$ to $j = 2$. Evaluating $\begin{aligned} \sum\limits_{j=1}^{2 }{({j^2 + 1})}&= (1^2 + 1) + (2^2 + 1) \\\\ &= 2 + 5 \\\\ &= 7\end{aligned}$ The answer $\sum\limits_{j=1}^{2 }{({j^2 + 1})}=7$